Write to Think 132 When is Earth closest to the sun? So why isn’t it the hottest time of year in Tucson? What do you think Earth would be like if it wasn’t tilted and it’s axis was exactly perpendicular to its orbit? What if it’s axis was tilted 900? What if it’s axis always pointed toward the sun?

To Do … Complete BOTH simulations and answer ALL the questions! Finished BOTH simulations and answered ALL the questions? Check answers to unl seasons simulations using answer sheet on front lab bench. Collect a front cover. Collate ALL your answers using the front cover as a guide. Check with someone else who’s finished that you’ve got it all and its correct! HAND IN … place in black tray! Get an Astronomy textbook from the back right of the lab … near the pod door. (Make sure you get the correct one!) Read about calendars on pages 8 and 9. Use internet to find out more. EX: when are we due to adjust the clocks and calendars in the future? By how much? Gravity review: Answer questions about “Gravity vs Distance’ at the top of page 18. Read all about moon phases, eclipses and tides pages 20 to 27 (We’ll be studying this next week!)

UNL SIMULATOR INTRUCTIONS Google ‘unl seasons simulator’ Click on the first link. Move the observer stick figure so that they are close to 32 degrees North. This is the latitude of Tucson, Arizona (You might be surprised with how far North that is!). Select BOTH labels boxes Play the animation. OBSERVE and SKETCH the location of the imaginary axis on the diagram for ‘How Earth Revolves around the sun’ . Now fill in the ‘Connecting Light Intensity to Temperature Tab’ Play the animation again. OBSERVE and RECORD the necessary information to fill out the table.

Modeling it with Cape Town 26.4 Indirect Weak Cold Winter

Season Questions Set the date to June 21st. CLASS SET: PLEASE LEAVE AT THE APPROPRIATE PLACE AT THE END OF THE LESSON Large left box Season Questions Top right box Answer the following on lined paper. Add sketches if you think they will help your explanations. Set the date to June 21st. Use the top right box to answer the following: Where is most of the direct light shining during June. Use the large left box to answer the following: What is causing the direct light to be shining in this area? Set the date to September 21st. Use the top right box to answer the following: Where is most of the direct light shining during September. Set the date to December 21st. Use the top right box to answer the following: Where is most of the direct light shining during December. Set the date to March 21st. Use the top right box to answer the following: Where is most of the direct light shining during March.

Example: 1a) In June the most direct light is shining on the Northern Hemisphere. I know this because there is a yellow circle that is indicating where most of the direct light is shining. It looks like it is shining on the tropic of cancer, which is about 9 degrees south of us. 1b) The direct light is shining on the Northern hemisphere because the tilt of Earth’s axis is TOWARD the sun (see large left box). That tilt causes the direct rays to shine on the Northern hemisphere. Yellow Dot Turn on Tucson Latitude How I found latitude for Tropic of Cancer Light shining directly on Northern Hemisphere

Direction of Sun Rays on Planet Earth (View from Side) Date Direction of Sun Rays on Planet Earth (View from Side) Sunlight Angle on Earth’s Surface Sun’s Altitude in degrees (ex. 80, 55, 35…) How direct are the sun’s rays? (Direct, In-between, Indirect…) How intense do you think the sunlight is? (Strong, Medium, Weak) What do you think the temperature is? (Hot, Medium, Cool/Cold) What Season is it in Tucson? June 22nd   September 23rd December 22nd March 21st

CLASS SET: PLEASE LEAVE AT THE APPROPRIATE PLACE AT THE END OF THE LESSON Determining the Sun’s Angle at Different Times of the Year Google ‘unl motions of the sun simulator’ Adjust the settings so they are the same as the ones on the back of this handout. Adjust the Day to June 21st. Where is the sun located in the sky? How can you tell? Sketch what you see. How much of a shadow can you observe on the person? Does this suggest the sun’s rays are direct or indirect? Adjust the Day to September 21st. Adjust the Day to December 21st. Adjust the Day to March 21st. The path of the sun in the sky over a year is called the analemma. Click the analemma box and observe the path. What does the analemma look like? Sketch it.

End of lesson